hariemmadi
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2006-10-30 10:25
(6360 d 05:22 ago)

Posting: # 334
Views: 5,252
 

 regarding the actual dosing time [Design Issues]

Dear sir/madam.

recently we have conducted a study, in which we have to dose 10 capsules to randomly seleceted couple of volunteers in a span of five minutes, but the dosing completion time will vary from subject to subject depending upon each subject. so our doubt is we have to document whether the start time of dosing or end time of dosing.for uniform maintainance we have documented start time of dosing, is this time is going to show any effcet during analysis and pharmacokinetic analysis.

let me the answer soon.

thanking u.
hari emmadi.
Helmut
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2006-10-30 16:27
(6359 d 23:19 ago)

@ hariemmadi
Posting: # 344
Views: 4,346
 

 oral dosing interval?

Dear Hari,

I'm not sure whether I do understand you completely...

❝ recently we have conducted a study, in which we have to dose 10 capsules to randomly seleceted couple of volunteers in a span of five minutes, but the dosing completion time will vary from subject to subject depending upon each subject.


Do you mean that every subject had to swallow 10 capsules within 5 minutes?

❝ so our doubt is we have to document whether the start time of dosing or end time of dosing.for uniform maintainance we have documented start time of dosing, is this time is going to show any effcet during analysis and pharmacokinetic analysis.


Yes this is correct; dosing starts with intake of the first capsule.
Otherwise (start time = intake of last capsule) imagine the following—only illustrative—example: the drug has a absorption half life of five minutes, and you start sampling every minute immediately after intake of the first capsule. In such a case you would get plasma concentrations at negative time points (because the first sampling point is recorded at t = -5 min). This would lead to a negative part of the AUC within t = -5 min and t = 0 ;-)
Most PK-software also interpolate from t=0/c=0 to the first measured concentration (i.e., the first trapezoid is actually a triangle); if you fiddle around with negative time points your AUC may be incorrect.

If I misunderstood your question, please correct me.

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hariemmadi
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2006-10-31 06:23
(6359 d 09:24 ago)

(edited by HS on 2006-10-31 12:32)
@ Helmut
Posting: # 346
Views: 4,151
 

 oral dosing interval?

dear sir,

thanks for ur reply. i have understand u, in our study, the volunteer have to consume 10 capsules wih in 5 minutes. (some volunteers have consumed with in one minute and some with in 2 and 3 minutes.) so please clarify me with some better example and whether to document the time of first intake or the time of last capsule intake. the study drug is Coenzyme Q 10.
Helmut
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Vienna, Austria,
2006-10-31 13:45
(6359 d 02:01 ago)

@ hariemmadi
Posting: # 349
Views: 4,263
 

 oral dosing interval?

Dear Hari!

❝ [...] in our study, the volunteer have to consume 10 capsules wih in 5 minutes.(some volunteers have consumed with in one minute and some with in 2 and 3 minutes.)


As already said, you did the right thing:
administration starts with intake of the first capsule, which sets t=0. Full stop :ok:

❝ so please clarify me with some better example and whether to document the time of first intake or the time of last capsule intake.


Excuse me, if my example was not clear enough...

❝ the study drug is Coenzyme Q 10.


At least according to the views of FDA Coenzyme Q10 is not a drug ;-)

P.S. Please avoid 'TOFU' (I edited your post).

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